T Araki1, L M Sholl2, H Hatabu3, M Nishino4. 1. Department of Radiology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA. Electronic address: taraki@partners.org. 2. Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA. 3. Department of Radiology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA. 4. Department of Radiology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA. Electronic address: mizuki_nishino@dfci.harvard.edu.
Abstract
AIM: To investigate the clinical and image features of thymic neuroendocrine tumours (NETs), and characterise the radiological patterns of recurrence and metastasis on serial imaging studies. MATERIALS AND METHODS: The study included 14 patients (11 males) with a histopathological diagnosis of thymic NETs (one typical carcinoid, eight atypical carcinoid, and five large cell neuroendocrine carcinoma). Preoperative images were assessed for features of primary tumours. Follow-up imaging studies were evaluated for the patterns of metastasis or recurrence. RESULTS: Underlying endocrine or autoimmune disorders were present in four patients (29%), including multiple endocrine neoplasia (MEN) type 1 (n=3) and autoimmune thyroiditis (n=1). On preoperative imaging, the primary tumours were commonly lobulate and heterogeneous, infiltrated the surrounding fat, and showed ≥50% abutment of the mediastinal structures, with the mean longest diameter of 14 cm (range: 4.1-28 cm). No significant differences of preoperative imaging features were noted among histopathological subtypes. Metastasis or recurrence was noted in 11 of the 14 patients (79%). Ten patients developed intrathoracic metastasis or recurrence, involving thoracic lymph nodes (n=7), pleura (n=4), lung (n=4), pericardium (n=4), and local recurrence in the postoperative mediastinum (n=3). Eight of the 11 patients also had extra-thoracic metastasis, involving bone (n=6), abdominal lymph nodes (n=4), liver, pancreas, kidney, adrenal gland, spleen and brain (n=1 for each site). CONCLUSIONS: Thymic NETs presented as a large, lobulate, heterogeneous mass with an infiltrative nature. Metastasis and recurrence were frequent, most commonly involving thoracic lymph nodes, while extra-thoracic metastasis to bones and abdominal lymph nodes were also noted.
AIM: To investigate the clinical and image features of thymic neuroendocrine tumours (NETs), and characterise the radiological patterns of recurrence and metastasis on serial imaging studies. MATERIALS AND METHODS: The study included 14 patients (11 males) with a histopathological diagnosis of thymic NETs (one typical carcinoid, eight atypical carcinoid, and five large cell neuroendocrine carcinoma). Preoperative images were assessed for features of primary tumours. Follow-up imaging studies were evaluated for the patterns of metastasis or recurrence. RESULTS: Underlying endocrine or autoimmune disorders were present in four patients (29%), including multiple endocrine neoplasia (MEN) type 1 (n=3) and autoimmune thyroiditis (n=1). On preoperative imaging, the primary tumours were commonly lobulate and heterogeneous, infiltrated the surrounding fat, and showed ≥50% abutment of the mediastinal structures, with the mean longest diameter of 14 cm (range: 4.1-28 cm). No significant differences of preoperative imaging features were noted among histopathological subtypes. Metastasis or recurrence was noted in 11 of the 14 patients (79%). Ten patients developed intrathoracic metastasis or recurrence, involving thoracic lymph nodes (n=7), pleura (n=4), lung (n=4), pericardium (n=4), and local recurrence in the postoperative mediastinum (n=3). Eight of the 11 patients also had extra-thoracic metastasis, involving bone (n=6), abdominal lymph nodes (n=4), liver, pancreas, kidney, adrenal gland, spleen and brain (n=1 for each site). CONCLUSIONS: Thymic NETs presented as a large, lobulate, heterogeneous mass with an infiltrative nature. Metastasis and recurrence were frequent, most commonly involving thoracic lymph nodes, while extra-thoracic metastasis to bones and abdominal lymph nodes were also noted.